Debt And Capital Lease Obligations (Narrative) (Details)			6 Months Ended
	Sep. 30, 2014 USD ($)	Mar. 28, 2013 USD ($)	Jun. 30, 2015 USD ($) item loan	Jan. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)	Mar. 27, 2013 USD ($)
Credit Facilities [Abstract]
Short term line of credit			$ 75,000,000
Notes [Abstract]
Restricted cash			7,723,000		$ 8,232,000
Short Term Line Of Credit [Member]
Credit Facilities [Abstract]
Maximum credit commitment			$ 75,000,000
Notes [Abstract]
Average Interest (in hundredths)			1.50%		1.50%
Fixed interest rate			1.50%
Series 2012-1 Asset-Backed Notes [Member]
Term Loans [Abstract]
Principal amount of loan			$ 171,000,000
Amount outstanding under the facility			$ 125,400,000
Notes [Abstract]
Fixed interest rate			3.47%
Series 2013-1 Asset-Backed Notes [Member]
Term Loans [Abstract]
Principal amount of loan			$ 229,000,000
Amount outstanding under the facility			$ 177,500,000
Notes [Abstract]
Fixed interest rate			3.35%
Revolving Credit Facility [Member]
Credit Facilities [Abstract]
Maximum amount credit facility might be increased			$ 960,000,000
Availability borrowing capacity			$ 384,900,000
Notes [Abstract]
Average Interest (in hundredths)			1.70%		1.90%
Revolving Credit Facility [Member] | Equipment [Member]
Credit Facilities [Abstract]
Net book value			$ 719,900,000
Revolving Credit Facility [Member] | CAI Rail Inc [Member]
Credit Facilities [Abstract]
Maximum credit commitment			250,000,000
Maximum amount credit facility might be increased			325,000,000
Availability borrowing capacity			$ 132,000,000
Notes [Abstract]
Average Interest (in hundredths)			1.90%		1.90%
Revolving Credit Facility [Member] | CAI Rail Inc [Member] | CAI Rail Assets [Member]
Credit Facilities [Abstract]
Net book value			$ 163,300,000
Revolving Credit Facility [Member] | Consortium of Banks [Member]
Credit Facilities [Abstract]
Revolving credit facility, maturity date			Mar. 15, 2020
Maximum credit commitment			$ 775,000,000	$ 760,000,000
Swing Line Loans [Member]
Credit Facilities [Abstract]
Maximum credit commitment			$ 10,000,000
Number of business days short term borrowings payable, Maximum			10 days
Standby Letters of Credit [Member]
Credit Facilities [Abstract]
Maximum credit commitment			$ 15,000,000
Letter of Credit [Member]
Credit Facilities [Abstract]
Letters of credit outstanding			100,000
Term Loan [Member] | Rental Equipment [Member]
Credit Facilities [Abstract]
Net book value			344,800,000
Term Loan [Member] | Development Bank of Japan [Member]
Term Loans [Abstract]
Principal amount of loan			$ 30,000,000
Term of loan			5 years
Number of quarterly installments | item			19
Quarterly payments of principal			$ 500,000
Debt instrument final payment			21,500,000
Amount outstanding under the facility			$ 26,400,000
Notes [Abstract]
Average Interest (in hundredths)			2.30%		2.20%
Term Loan [Member] | Consortium of Banks [Member]
Term Loans [Abstract]
Amount outstanding under the facility		$ 125,000,000				$ 249,400,000
Proceeds used to repay credit facility		124,400,000
Notes [Abstract]
Average Interest (in hundredths)			1.90%		1.80%
Term Loan [Member] | Consortium of Banks, Note Dated October 1, 2014 [Member]
Credit Facilities [Abstract]
Maximum credit commitment	$ 115,000,000		$ 150,000,000
Term Loans [Abstract]
Amount outstanding under the facility			143,300,000
Term Loan [Member] | Consortium of Banks, Note Dated April 11, 2012 [Member]
Credit Facilities [Abstract]
Maximum credit commitment			142,000,000
Maximum amount credit facility might be increased			$ 200,000,000
Term Loans [Abstract]
Term of loan			5 years
Amount outstanding under the facility			$ 114,400,000
Periodic payments specified as percentage of drawn amount (in hundredths)			1.75%
Notes [Abstract]
Average Interest (in hundredths)			1.90%		1.90%
Term Loan [Member] | London Interbank Offered Rate (LIBOR) [Member] | Consortium of Banks, Note Dated October 1, 2014 [Member]
Term Loans [Abstract]
Basis spread on variable rate (in hundredths)	2.25%		1.60%
Senior Secured Notes [Member]
Term Loans [Abstract]
Amount outstanding under the facility			$ 82,400,000
Notes [Abstract]
Long-term debt			$ 103,000,000
Average Interest (in hundredths)			4.90%		4.90%
Percentage of aggregate principal to prepay, minimum (in hundredths)			10.00%
Senior Secured Notes [Member] | Rental Equipment [Member]
Credit Facilities [Abstract]
Net book value			$ 105,400,000
Asset-Backed Notes [Member]
Term Loans [Abstract]
Proceeds used for working capital purposes		$ 229,000,000
Notes [Abstract]
Average Interest (in hundredths)			3.40%		3.40%
Asset-Backed Notes [Member] | Rental Equipment [Member]
Credit Facilities [Abstract]
Net book value			$ 371,600,000
Collateralized Financing Obligations [Member]
Notes [Abstract]
Long-term debt			$ 135,300,000
Average Interest (in hundredths)			0.80%		0.80%
Obligations [Abstract]
Average fixed and floating interest rates			0.80%
Maturity date range start			Sep. 01, 2015
Maturity date range end			Jun. 01, 2019
Amortizing Term Loan [Member] | Consortium of Banks [Member]
Credit Facilities [Abstract]
Maximum credit commitment			$ 300,000,000
Term Loans [Abstract]
Term of loan			6 years
Capital Lease Obligations [Member]
Obligations [Abstract]
Average fixed and floating interest rates			2.80%
Maturity date range start			Sep. 01, 2015
Maturity date range end			Mar. 01, 2016
Capital lease obligations			$ 100,000
Capital Lease Obligations [Member] | Containers [Member]
Credit Facilities [Abstract]
Net book value			$ 100,000
Variable Interest Entity, Primary Beneficiary [Member] | Term Loan [Member]
Term Loans [Abstract]
Number of loans | loan			2
Notes [Abstract]
Long-term debt			$ 8,900,000
Average Interest (in hundredths)			2.50%		2.60%
Variable Interest Entity, Primary Beneficiary [Member] | Term Loan [Member] | Rental Equipment [Member]
Credit Facilities [Abstract]
Net book value			$ 18,500,000
Variable Interest Entity, Primary Beneficiary [Member] | Amortizing Term Loan [Member]
Term Loans [Abstract]
Term of loan			5 years
Notes [Abstract]
Long-term debt			$ 9,200,000
Fixed interest rate			2.70%
Variable Interest Entity, Primary Beneficiary [Member] | Non-Amortizing Term Loan [Member]
Term Loans [Abstract]
Term of loan			5 years
Notes [Abstract]
Long-term debt			$ 1,600,000